From U.S. Pat. No. 3,044,105 and the Swedish Pat. No. 227,018 it is known to use detachable handles for carrier bags, boxes, suitcases and like containers of cardboard or similar material, which handles are made of molded non-rigid plastics, are provided at their ends with elongate locking plates which extend in the longitudinal direction of the handle, and are intended to be inserted into slots punched in the container to secure the handle thereto. Difficulties were encountered with earlier handles of this type, particularly in connection with the mounting thereof on the container.